For companies that have geographically dispersed offices, such as remote offices/branch offices (ROBOs) or other satellite locations, a turnkey solution for desktop virtualization can speed deployment at the enterprise edge.

A new Cisco Validated Design (CVD) for Citrix XenApp and XenDesktop uses a predesigned, self-contained platform—the FlexPod Data Center with Cisco UCS Mini—that makes it easy to provision reliable desktops and applications from 350 to 700 users.

The FlexPod Data Center, co-designed by Cisco and NetApp, integrates compute servers, networking fabric, and hybrid storage components, creating a standalone, drop-in VDI/SBC solution that can be installed at remote sites and yet managed centrally.

A Flexible Turnkey Solution

FlexPod Data Center with Cisco UCS Mini is the underlying building block that simplifies deployment while supporting density growth and proven mixes of XenApp and XenDesktop workloads. While FlexPod provides a cookie-cutter solution, this CVD demonstrates how the solution is also quite versatile.

Deployments can share a common architecture, component design, configuration procedures, and management. At the same time user capacity can scale and expand to increase the number of hosted shared desktops (RDS) or hosted pooled virtual desktops (VDI). This scalability also benefits small and mid-sized businesses—they can start small and grow from 350 to as many as 700 users.

The CVD describes a base 4-blade FlexPod with Cisco UCS Mini configuration that supports 350 users (150 RDS and 200 VDI users). Cisco UCS B200 M4 Blade Servers were added to this base configuration to support workload expansion and scale density. All configurations followed a fault-tolerant N+1 design for infrastructure and RDS/VDI VMs. To size and validate density combinations, we conducted single and multiple blade server scalability tests using Login VSI software. The complete CVD documents the step-by-step procedures we used to create the test environment, the test configurations, and includes all of the test results.

Figure 1: Reference architecture components in the FlexPod with Cisco UCS Mini


Solution Overview

Figure 1 shows the key components in the CVD reference architecture, including:

  • Citrix XenApp and XenDesktop 7.6 software. Because Citrix XenDesktop 7.6 unifies the functionality of earlier XenApp and XenDesktop releases, the same software and same PVS Setup Wizard can provision both RDS sessions (on Windows Server 2012 R2) and pooled hosted VDI desktops (running Microsoft Windows 7 or Windows 8). In the CVD all infrastructure and RDS/VDI workload servers were 100% virtualized on VMware vSphere ESXi 5.5 Update 2.
  • Cisco UCS Mini. The Cisco UCS Mini combines servers, storage, and a 10 Gigabit networking fabric in an easy-to-deploy, compact form factor. The chassis can support up to eight half-width Cisco UCS B200 M4 Blade Servers, each featuring dual 10-core 2.6 GHz Intel Xeon (E5-2660v3) processors and 256GB. In this CVD, between four and seven blade servers were configured for the various test cases.Two Cisco UCS 6324 Fabric Interconnects provide redundant, high bandwidth LAN and storage connectivity for the blade servers and the chassis, and can optionally connect to rack servers as well. Cisco UCS Manager manages all Cisco UCS Mini software and hardware components, and Cisco UCS Central can aggregate multiple UCS Manager domains for comprehensive policy control and centralized management.
  • Cisco Nexus 9372 Switches. To support 10 GbE connectivity for the FlexPod solution, these Layer 2/Layer3 access switches each feature 48 1/10-Gbps Small Form Pluggable Plus (SFP+) ports and 6 Quad SFP+ (QSFP+) uplink ports. In addition, the Nexus 9373 is Cisco ACI capable.
  • NetApp FAS2552 hybrid storage. The NetApp FAS2552 is a dual controller storage system that combines low-latency SSDs for caching and cost-effective SAS drives for capacity. The array configuration used in the testing included four 200GB SSDs and twenty 900GB SAS drives. The array controllers feature 10GbE ports to support blade server boot over iSCSI and NFS/CIFS connectivity for file system access.

Key Solution Advantages

The CVD architecture offers significant benefits to enterprise-edge or small business deployments:

  • Self-contained and compact solution. The FlexPod with UCS Mini architecture defines an entirely self-contained “all-in-one” solution with the infrastructure needed to support a mix of up to 700 Citrix XenApp and XenDesktop users. The solution consumes only 10 rack units and fits in less than a single data center rack, conserving valuable rack space.
  • Cost-effective and scalable desktop virtualization for the enterprise edge. Powerful Cisco UCS blade servers enable high user densities at a low cost per seat. By adding additional blade servers to the chassis, a basic 4-server configuration supporting 350 users scales easily to support another 350 additional XenApp and XenDesktop users. The NetApp storage array features a combination of low-latency flash devices and a tray of less expensive SAS drives, for economical I/O over an end-to-end Ethernet fabric.
  • Fault-tolerant design. The architecture defines redundant infrastructure and workload VMs across multiple physical Cisco UCS blade servers, optimizing availability to keep users productive.
  • Easy to deploy and manage. UCS Manager can monitor and manage Cisco UCS servers in the FlexPod solution along with other Cisco UCS blade and rack servers in the management domain. Cisco UCS Central can extend management across Cisco UCS Manager domains to centralize management across multiple remote sites.
  • Fully validated and proven solution. The CVD defines a reference architecture that has been tested under aggressive usage scenarios, including boot and login storms. Test requirements mandated that each configuration boot within 15 minutes and complete logins in 48 minutes at the peak user densities tested.

Test Cases and Main Findings

Test engineers conducted five different test cases (Figure 2). The first two examined single server scalability for RDS and VDI respectively, determining the recommended maximum density for each workload type on a single Cisco UCS B200 M4 blade with dual Intel® E5-2660 v3 processors and 256GB of RAM. The other three tests analyzed the performance of mixed workloads on multiple blade servers.

Figure 2: Five test cases were run to examine single server and multiple server scalability


Multiple blade testing showed that the configurations could support mixed workload densities under simulated stress conditions (cold-start boot and simulated login storms). In these test cases, the FlexPod with UCS Mini solution performed well under the configured RDS/VDI user mix, providing reasonable response times with the Login VSI Office Worker workload. The NetApp hybrid storage easily handled IOPS requirements with average read and write latencies less than 5ms. During all tests, extensive performance metrics were collected and are published in the full CVD.

The test results show how easily FlexPod with UCS Mini configurations can expand and flex, allowing deployments at the enterprise edge to grow and support larger RDS and VDI capacities. To learn more about the solution and our testing, you can download the complete CVD here.

— Rob Briggs, Principal Solutions Architect, Citrix Systems, Inc.

— Frank Anderson, Senior Solutions Architect, Cisco Systems, Inc.